mewrox99 - 12-6-2010 at 00:06
Dr. N Butyl Lithium makes a phosphorescent powder from microwave combustion synthesis using:
Watch: http://www.youtube.com/watch?v=TYDn06G2C0E
1.875g of Aluminum Nitrate Nonahydrate
530mg Strontium Nitrate
10.7mg Europium Nitrate Pentahydrate
21.9mg Dysprosium Nitrate Pentahydrate
30.9mg Boric Acid
3mL distilled water is used as the solvent.
3.9g of Urea is added to that mixture and it is shaken until fully dissolved.
It can be ignited in a vile by torch but this yields lower quality product.
It is ignited by placing the vile in a beaker and microwaving. This ignites the mixture.
My question. What products are formed? And what reactions are taking place during the combustion.
Picric-A - 12-6-2010 at 01:22
The product is mostly Aluminium oxide, doped with Strontium, Europium and Dysprosium oxide with a trace of boric oxide to act as a light intensifier.
I am unsure as to the purpose of the urea however.
The_Davster - 12-6-2010 at 04:15
Rare earth-doped strontium aluminate.
I have prepared this by sol-gel synthesis and then calcining, but this procedure seems far easier. I think urea is the solvent (at high T once water
is driven off) and microwave absorber in this case, but I could be wrong.
Your nitrates are calcined to the corresponding oxides. Under the high temperatures the strontium aluminate structure is formed.
Vogelzang - 12-6-2010 at 06:22
Ultra Green powder. I think its doped Strontium Aluminate.
http://www.4shared.com/video/SwsjOVD5/Luminescent.html
http://shop.ebay.com/i.html?_nkw=ultra+green+powder&_sac...
[Edited on 12-6-2010 by Vogelzang]
not_important - 12-6-2010 at 09:53
Vogelzang has it. The urea functions as a reducing agent to form Eu(II), and as a fuel to generate additional heat. Boric oxide functions as a flux.
Lotta stuff about it on da web
Microwave Synthesis of a Long-Lasting Phosphor
http://pubs.acs.org/doi/abs/10.1021/ed086p72
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